Then came Autofill
Modern mobile platforms support the Autofill Feature. This allows password managers to integrate with the operating system and add hooks to login screens of other apps and web browser pages. Usually, the app will show a small AltoPass pop-up right underneath the username field. Upon selecting the right account, both username and password fields will be automatically filled in. Consequently, you don't need to worry about switching back and forth between the AltoPass app and your account while also having to copy/paste your credentials.
Mobile platforms require the user to authorize a specific application for the role of the autofill source. AltoPass provides detailed guidelines on how to enable autofill. Go to Settings->Autofill in your mobile app and follow the steps.